1. Field of the Invention
This invention relates to a radiation image read-out apparatus, an image transmission apparatus, and a radiation image read-out and reproducing apparatus utilizing the radiation image read-out apparatus. This invention particularly relates to an improvement in an apparatus for reading out a radiation image having been stored on a stimulable phosphor sheet, an apparatus for transmitting an image through an optical fiber bundle, and a radiation image read-out and reproducing apparatus utilizing the improved radiation image read-out apparatus.
2. Description of the Prior Art
It has been proposed to use stimulable phosphors in radiation image recording and reproducing systems. Specifically, a radiation image of an object, such as a human body, is recorded on a sheet provided with a layer of the stimulable phosphor (hereinafter referred to as a stimulable phosphor sheet). Picture elements in the radiation image, which has been stored on the stimulable phosphor sheet, are then successively scanned with stimulating rays, such as a laser beam, which cause the stimulable phosphor sheet to emit light in proportion to the amount of energy stored thereon during its exposure to radiation. The light, which is successively emitted from the picture elements on the stimulable phosphor sheet, upon stimulation thereof, is photoelectrically detected and converted into an electric image signal. The stimulable phosphor sheet, from which the image signal has been detected, is exposed to erasing light, and energy remaining on the stimulable phosphor sheet is thereby released.
The image signal, which has been obtained with the radiation image recording and reproducing systems, is subjected to image processing, such as gradation processing or frequency processing, such that a visible radiation image having good image quality can be reproduced and used as an effective tool in, particularly, the accurate and efficient diagnosis of an illness. The image signal having been obtained from the image processing is used for reproducing a visible image on photographic film or displaying the visible image on a high definition cathode ray tube (CRT) display device. The reproduced visible image is used, for example, in making a diagnosis by a medical doctor, or the like. The stimulable phosphor sheet, from which the remaining energy has been released by its exposure to the erasing light, can be repeatedly used for the recording of a radiation image.
However, in radiation image read-out apparatuses which are employed in the radiation image recording and reproducing systems described above, it is necessary to use a high-quality laser beam as the stimulating rays and to use an expensive photomultiplier as means for photoelectrically detecting the light emitted by the stimulable phosphor sheet. Further, it is necessary for the radiation image read-out apparatuses to be provided with a laser beam scanning system and a converging optical system for detecting the light emitted by the stimulable phosphor sheet as signals, each of which represents one of the picture elements. Therefore, the cost of the radiation image read-out apparatuses cannot be kept low. The high cost of the radiation image read-out apparatuses is one of obstacles to the promotion of wide use of the radiation image recording and reproducing systems.